<!DOCTYPE html>

<style>
  #parent { position: relative; left: 40px; top: 40px; width: 120px;
           height: 120px; overflow: hidden; border-radius: 10px;
           background-color: blue;
  }
  #child { position: relative; left: 140px; top: 140px; width: 100px;
           height: 100px; background-color: green;
           transform: translate(-120px, -120px);
           will-change: transform;
  }
</style>
<div id='parent'>
  <div id='child'></div>
</div>
